Efficient multipartite entanglement concentration of electron-spin state with charge detection

TL;DR

This paper introduces two efficient protocols for concentrating multipartite electron-spin entanglement using charge detection, with the second protocol being more optimal for repeated applications and higher success rates.

Contribution

The paper proposes novel entanglement concentration protocols for three-electron W states utilizing charge detection and polarization beam splitters, improving success probability and reusability.

Findings

Second protocol achieves higher success probability.

Protocols enable concentration with only single charge qubits.

Repetitive use enhances entanglement concentration efficiency.

Abstract

We present two entanglement concentration protocols (ECPs) for arbitrary three-electron W state based on their charges and spins. Different from other ECPs, in both two ECPs, with the help of the electronic polarization beam splitter (PBS) and charge detection, the less-entangled W state can be concentrated into a maximally entangled state only with some single charge qubits. The second ECP is more optimal than the first one, for by constructing the complete parity check gate, the second ECP can be used repeatedly to further concentrate the less-entangled state and obtain a higher success probability. Therefore, both the ECPs, especially the second one may be useful in current quantum information processing.